38,119 research outputs found
Ginsparg-Wilson fermions: practical aspects and applications
I review recent progress in the implementation of lattice fermions satisfying
the Ginsparg-Wilson relation and some physical applications.Comment: 6 pages, Talk at Lattice 2001(plenary
Two-Cutoff Lattice Regularization of Chiral Gauge Theories
I review our method to formulate chiral gauge theories on the lattice based
on a two-cutoff lattice regularization, and discuss recent numerical results in
a chiral U(1) gauge theory in 2D.Comment: Based on invited talk at AIJIC 97 on Recent Developments in
Non-Perturbative Methods, Seoul, Korea. 20 page
Neutrino Physics
This is the writeup of the lectures on neutrino physics delivered at various
schools: TASI and Trieste in 2013 and the CERN-Latin American School in 2015.
The topics discussed in this lecture include: general properties of neutrinos
in the SM, the theory of neutrino masses and mixings (Dirac and Majorana),
neutrino oscillations both in vacuum and in matter, as well as an overview of
the experimental evidence for neutrino masses and of the prospects in neutrino
oscillation physics. We also briefly review the relevance of neutrinos in
leptogenesis and in beyond-the-Standard-Model physics.Comment: 58 pages, contribution to the CERN in the Proceedings of the 2015
CERN-Latin-American School of High-Energy Physics, Ibarra, Ecuador, 4 - 17
March 2015. arXiv admin note: text overlap with arXiv:1010.413
Simple model for the phase coexistence and electrical conductivity of alkali fluids
We report the first theoretical model for the alkali fluids which yields a
liquid-vapor phase coexistence with the experimentally observed features and
electrical conductivity estimates which are also in accord with observations.
We have carried out a Monte Carlo simulation for a lattice gas model which
allows an integrated study of the structural, thermodynamic, and electronic
properties of metal-atom fluids. Although such a technique is applicable to
both metallic and nonmetallic fluids, non-additive interactions due to valence
electron delocalization are a crucial feature of the present model.Comment: RevTex, 11 pages, 2 ps figure files appended, submitted to PR
Study of theoretical models for the liquid-vapor and metal-nonmetal transitions of alkali fluids
Theoretical models for the liquid-vapor and metal-nonmetal transitions of
alkali fluids are investigated. Mean-field models are considered first but
shown to be inadequate. An alternate approach is then studied in which each
statistical configuration of the material is treated as inhomogeneous, with the
energy of each ion being determined by its local environment. Nonadditive
interactions, due to valence electron delocalization, are a crucial feature of
the model. This alternate approach is implemented within a lattice-gas
approximation which takes into account the observed mode of expansion in the
materials of interest and which is able to treat the equilibrium density
fluctuations. We have carried out grand canonical Monte Carlo simulations, for
this model, which allow a unified, self-consistent, study of the structural,
thermodynamic, and electronic properties of alkali fluids. Applications to Cs,
Rb, K, and Na yield results in good agreement with observations.Comment: 13 pages, REVTEX, 10 ps figures available by e-mail
Zero sound density oscillations in Fermi-Bose mixtures
Within a mean field plus Random-Phase Approximation formalism, we investigate
the collective excitations of a three component Fermi-Bose mixture of K atoms,
magnetically trapped and subjected to repulsive s-wave interactions. We analyze
both the single-particle excitation and the density oscillation spectra created
by external multipolar fields, for varying fermion concentrations. The
formalism and the numerical output are consistent with the Generalized Kohn
Theorem for the whole multispecies system. The calculations give rise to
fragmented density excitation spectra of the fermion sample and illustrate the
role of the mutual interaction in the observed deviations of the bosonic
spectra with respect to Stringari's rule.Comment: 9 pages, 6 eps figures, submitted to Phys.Rev.
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